Trigeminal neuralgia, also known as tic douloureux, is a painful disorder of a nerve in the face called the trigeminal nerve or fifth cranial nerve. There are two trigeminal nerves, one on each side of the face. These nerves are responsible for detecting touch, pain, temperature and pressure sensations in areas of the face between the jaw and forehead.
People who have trigeminal neuralgia usually have episodes of sudden, intense, "stabbing" or "shocklike" facial pain. This pain can occur almost anywhere between the jaw and forehead, including inside the mouth. However, it usually is limited to one side of the face.
In some cases, the cause of trigeminal neuralgia is unknown. In many people, however, something seems to be irritating the trigeminal nerve, usually in the area of the nerve's origin deep within the skull. In most cases, the irritation is believed to be caused by an abnormal blood vessel pressing on the nerve. Less often, the nerve is being irritated by a tumor in the brain or nerves. Sometimes, the problem is related to a rare type of stroke. In addition, up to 8% of patients who have multiple sclerosis (MS) eventually develop trigeminal neuralgia as a result of MS-related nerve damage.
New cases of trigeminal neuralgia affect 4 to 5 of every 100,000 people in the United States each year. It affects women slightly more often than men, possibly because the disease is most common in older people and women live longer. The first episode of facial pain usually occurs when the patient is 50 to 70 years old. Although infants, children and young adults may develop this disorder, it is rare in people younger than age 40.
Symptoms
Trigeminal neuralgia causes episodes of sudden, intense facial pain that usually last for two minutes or less. In most cases, the pain is described as excruciating, and its quality is "sharp," "stabbing," "piercing," "burning," "like lightning" or "like an electric shock." In most cases, only one side of the face is affected.
The pain of trigeminal neuralgia is recognized as one of the most excruciating forms of pain known. The pain often is triggered by nonpainful facial movements or stimuli, such as talking, eating, washing the face, brushing the teeth, shaving or touching the face lightly. In some cases, even a gentle breeze on the cheek is enough to trigger an attack. Approximately 50% of patients also have specific trigger points or zones on the face, usually located somewhere between the lips and nose, where an episode of trigeminal neuralgia can be triggered by a touch or a temperature change. In some cases, a sensation of tingling or numbness comes before the pain.
Attacks of trigeminal neuralgia can vary significantly, and may occur in clusters, with several episodes following in series over the course of a day. For unknown reasons, trigeminal neuralgia almost never occurs at night when the person is sleeping.
Some patients also have a cheek twitch or muscle spasm, wincing, a facial flush, a tearing eye or salivation on the same side of the face. It is the facial muscle spasms that led to the older term, tic douloureux (in French, tic means muscle twitch or spasm; douloureux means painful).
Diagnosis
Your doctor will ask about your symptoms and your medical history, including any history of multiple sclerosis, a condition that may cause similar or even identical symptoms. To help rule out medical and dental conditions that can have similar symptoms, your doctor also will ask whether you have a history of:
- Recent trauma to your face or teeth
- A recent tooth infection or root canal treatment
- A tooth extraction on the same side as your facial pain – Sometimes a tooth extraction can cause pain in the area of the missing tooth.
- Any areas of painful facial blisters – Painful blisters can be a sign that you have a viral infection involving your facial skin, such as herpes (which is caused by the herpes simplex virus) or shingles (which is caused by varicella zoster, the chickenpox virus). Facial pain can last for weeks after the blisters heal, especially in cases of shingles.
Next, your doctor will thoroughly examine your head and neck, including the area inside your mouth. The doctor also will do a brief neurological examination and concentrate on feeling and muscle movements in your face. In almost all cases of trigeminal neuralgia, the results of these examinations are normal. If necessary, your doctor will order a magnetic resonance imaging (MRI) or computed tomography (CT) scan of your head to check for blood vessel abnormalities, tumors pressing on your trigeminal nerve or other possible causes of your symptoms.
Your doctor will diagnose trigeminal neuralgia based on your symptoms, the examination and test results. There is no specific test to confirm the diagnosis of trigeminal neuralgia, so an important part of the diagnosis is excluding other explanations for the symptoms.
Expected Duration
Trigeminal neuralgia is unpredictable. For unknown reasons, many people experience periods when the illness suddenly gets worse and causes repeated painful episodes over several days, weeks or months. This period may be followed by a pain-free interval that can last for months or years.
The type of treatment may influence how long your symptoms last. Some treatments carry a higher risk that the symptoms will return.
Prevention
Because the cause of trigeminal neuralgia is unknown, it cannot be prevented.
Treatment
The first treatment for trigeminal neuralgia usually is carbamazepine (Tegretol and others). Carbamazepine is an anticonvulsant medication that decreases the ability of the trigeminal nerve to fire off the nerve impulses that cause facial pain. If carbamazepine is not effective, other possible drug choices include phenytoin (Dilantin), gabapentin (Neurontin), lamotrigine (Lamictal), topiramate (Topamax), and valproic acid (Depakene, Depakote). A muscle relaxant such as baclofen (Lioresal) can be tried alone or in combination with an anticonvulsant. Narcotic pain relievers, such as oxycodone, hydrocodone or morphine (several brand names), may be taken briefly for severe episodes of pain.
Some of these medications carry the risk of unpleasant side effects, including drowsiness, liver problems, blood disorders, nausea and dizziness. For this reason, people taking any of these medications may be monitored with frequent follow-up visits and periodic blood tests. After a few pain-free months, your doctor may attempt to decrease the dose of the medication gradually or discontinue it. This is done to limit the risk of side effects and to determine whether your trigeminal neuralgia has gone away on its own.
If medication does not stop your pain or if you cannot tolerate the side effects of medication, then your doctor may suggest one of the following treatment options:
- Rhizolysis – In this approach, part of the trigeminal nerve is inactivated temporarily by using one of the following methods: a heated probe, an injection of the chemical glycerol or a tiny balloon that is inflated near the nerve to compress it. During the procedure a needle or a tiny hollow tube called a trocar is inserted through the skin of your cheek. These procedures provide immediate relief in up to 99% of patients, but 25% to 50% of people will have the problem return during the next several years.
- Stereotactic radiosurgery – This form of radiation therapy uses a linear accelerator or a gamma knife to inactivate part of the trigeminal nerve. After your head is positioned carefully in a special head frame, many tiny beams of radiation are aimed precisely at the part of the trigeminal nerve that must be inactivated. Stereotactic radiosurgery is a fairly new treatment option for trigeminal neuralgia, and its long-term success rate is still being evaluated.
- Microvascular decompression of the trigeminal nerve – In this delicate surgical procedure, a surgeon carefully repositions the blood vessel that is pressing on your trigeminal nerve near your brain. Because this procedure involves opening your skull, the ideal candidate for this procedure is someone who is generally healthy and younger than 65. Overall, the immediate success rate is approximately 90%, and 70% to 80% of patients have long-term relief. Microvascular decompression may be effective for patients who have not had success with one of the less invasive surgeries.
When To Call a Professional
You should seek medical help immediately if you develop facial pain that fits the pattern of trigeminal neuralgia.
Prognosis
In most cases, the outlook is good. Approximately 80% of patients become pain free with medication alone. When medication fails or produces unwanted side effects, other treatment options are available and also have a high rate of success.